Water-heating and steam-generating boiler



Aug. 31,1926. *1,598,113

W. BENNIS WATERI HEATING AND STEAM GENERAT'ING BOLER Filed August 5Y 1925 Sheets she et 2 Wiesse y -mmr l, 9mm

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Application filed August 3, 1925, Serial No. 47,930, and in England August 1, 1924.

.45 may pass down through one section of a bank or banks 'of steam generating tubes and 'then upthrough another'section of said `tubes,vthe said tubes being vpreferably'inclined to ensure proper circulation. The invention is more particularly described with reference to the accompanying drawings, in which:

Figure 1 is a sectional side' elevation through one form of construction.

Figure 2 is a corresponding view of a modified form of construction.

Figure 3 shows a sectional side elevation of a third form of construction.V Figure l is asimilar view showing the 3. arrangement of the present invention aplplied to a, two pass boiler.

Figure 5 1s a view of an arrangementv of.

the present invention applied to a two pass 'boiler with'additional heating tubes to those l shown in Figure 4, and the consequential arrangement 'of these tubes. Figure 6 is a sectional elevation of Figure 5,

The gases of combustion from' a burner or burners 1 mounted at the top ot the com? gbustion chamber 2 which may be adapted forI the burning of powdered liquid or gaseous fuel, pass down through boiler tubes 3, 4, which form the whole or the major poru tion of the water heating surface ot the boiler. The gases may then pass upwards or radially outwards and into a. tlue which may contain an air heater or economizer. The usual super-heating'tubes' 6 can be Aproo vided between the rst and second groups 'of boiler tubes 3. ll. These boiler tubes are connected at their, ends to head-ers 7 as shown,

, or to water legs or drums.l These headers are connected to the steam drums 8, 8, by

5B circulating pipes E), .10, the pipes 9 preterabjy forming a water cooling surface for the walls -for the furnace. ln the arrangement shown, the'water will pass down from thel steam drum 8 by means ot the pipes 10, and through the groups of tubes 3, L1, whereupon the heated water passes upwards tothe steam drums 8, 8a, through the tubes 9,.

The floor 11 receiving the ash or the like vsolid residue ot1 combustion is preferably water cooled by the provision of a series of tubes 12 lying in spaced relationship along it and con'i'ected to a water header 13 at one end, and to a mud ldrum 14 at the other end,l whichV mud drum 14E is, connected to the headers 7 on one side of the boiler by means of a pipe 15, whilst the water header 13 is. connected to water headers 7 at vthe other side of the boiler by means of a pipe 15, .thus providing a water cooling surface for the floor 11 of the furnace. AWhilstthese -tubes are'. shown laid upon the brickwork floor, they may be arranged in open grooves or closed passages within thisfloor, if de` sired.

In the modified arrangement shown in Figure 2 the ash and the like solid residue from the co'mbustion falls into hoppers 16 which may be provided with discharge devices. This iig-ure shows,-by way .of example, the application of a water screen 17 arranged above the iioor of the ash hopper. The gases ot' combustion in this case will, therefore, pass through the irstbank of tubes 18, hthen 'over the superheater tubes 19, then over a second bank of tubes 20,

then over the tubes 17 forming the water screen, andthen outwards through the flue 38 upwards and out through the flue 39 which may include an economizer, air heater or both such elements. p t

Inl the boiler arrangement shown inFigure 3, the tirst and second main 'oups of tubes of the boiler 21. 9,2 ..1espect1vely, are inclined in ditferentdirections to one another, the steam drum 23 being itseli:` vbelow the level of the burners 1, so that the whole of the boiler lies below the burners 1 and. the combustion chamber 2.

Inthis arrangement the furnace is Shown vby way of example to have a floor which itself forms an ash or the likeretuse collecting hopper 23, which may be provided with any vknown form of discharge device, such as 24.- The Hoor ot this hopper may similarly be protected by means of a' series of vwater t-ubes 25 which form part of the water circulating system of the boiler.

Also in this case it will be seen that the gases of combustion from the combustion chamber 2 pass through the main tubes of the boiler in a downward direction, and thence outwards and upwards, whence they pass into the exit iiue 26 which may contain an air heater, economizer or the like. j

The arrangement of the present invention is also applicable to multiple pass boilers, as shown in Figure 4, where the gases of combustion pass through the water tube groups 27, 28, forming the boiler in double pass, these tubes being divided into two passes by a partition wall 29.

The combustion chamber 2 and the outlet ue 30 are separated by suspended walls 3l, 32, whichpreferably have anair space 33 between them, and are supported in such a" manner that the tubes 27 are not called upon to bear any portion of the weight of suchl walls.

If desired, the space 33 between the walls 31, 32 may be closed and air circulated through this space, which can, therefore, be

used as a pre-heating means for the air to be used for the purpose of' combustion.

In addition to the super-heater or superheater units shown in the drawings, an interstage re-heater may be used within a suitable location and in appropriate location to the main steam generating tubes of the boi'ler, such re-heater supplying heat energy to the steam discharged from the high pressure section of a steam turbine or engine and delivered to thelow pressure section of such steam turbine or engine after again being subject to the heat of combustion -in the furnace. i

' A rime advantage of the present invenytion 1s that the evaporative eiici'ency of the heating surface when placed below the combustion chamber is materially greater, per unit of-surface, than when placed in the ordinary manner above or substantially above or at the side of the combustion chamber, as has hitherto been thepractice, this effect being especially the case when, according to my invention, the flame and gases of combustion are caused to pass directly through the steam generating tubes in one or more passes. l

In addition to the main boiler'tubes ad-v ditional heating tubes-34: in suitable connection with headers or drums 35, can be provided, either upon or spaced' slightly away from, the enclosing walls of the furnace, and these maybe provided with fins or ribs of steel or iron welded to or formed integral with them to increase the effective heating surface of these tubes. An economizer may be advantageously placed at 30 in the construction according to Figure 5.

I declare that what I claim is:

l. A waterheating and steam generating boiler comprising a combustion chamber, a heating chamber below said combustion chamber in open communication therewith, banks of substantially horizontal boiler tubes situated within said heating chamber heating chamber below said combustion chamber in open communication therewith, banks of substantially horizontal boiler tubes situated within said heating chamber and forming part of the effective heatin surface of the boiler system, vertical hea ers to which the banks of tubes are connected at their ends, xsteam drums connected to the vertical headers, fuel jets inthe roof of the combustion chamber for projecting the gases of combustion downwardly through said banks of boiler tubes, and a water cooled floor for said combustion chamber in the form of a collecting hopper adapted to receive the solid residue or ash from the products of combustion.

3. A water heating and steam generating boiler comprising a combustion chamber, a heating chamber below said combustion chamber in open communication therewith, banks of substantially horizontal boiler tubes situated within said heating chamber and forming part of the eifective heating surface of the boiler system, vertical 'headers to which the banks of tubes are connected at their ends, steam drums connected to the combustion chamber for projecting the gases of combustion downwardly through said banks of boiler tubes, a passage for the upward flow of the gases after their iiow through the said banks of boiler tubes, a combustion air preheating device comprising a hollow suspended wall separating such passage from the combustion chamber, and a water cooled floor for said combustion chamber adapted to receive the solid residue or' ash from the products of combustion.

4. A water heating and steam generating boilerv comprising a combustion chamber, a heating chamber below said combustion chamber in open communication therewith, banks of substantially horizontal boiler tubes situated within said heating chamber and forming part of the eective heating surfaoe of the boiler system, Yertioal'headf ers to which the banks of'jsubes are connect# ed at their ends, steam drumseonnected to the Vertical headers, -fuel jets in the roof' 'of the combustion chamber forprojeoting,

the gases of Combustion `downwardly through said banks' of boiler'tubes, a passage for the upward flow of'thefgases after -their How thro-ugh the Said bank of boiler tubes, a'j hollow vsuspended,wall separating such passage from Jhe combustion -Chamber,

means to circulate air through ahesaid hoh low wall to be heated and-thenusedjfw Jolie purpose of combustiomanda watercooled floor fory saidooinbustion chamber adapted to receive 'the solid residue 0-1"asli vfrom the products4 of`oonibustion.

5. A water heating andsteain generain'g boiler comprising a combustion Chamber, a heating chamber below said combustion chamber in open oomniunioation tliereviibhv banksA of substantially horizontal boiler tubes; situated within said ,heating chamber and forming' partofthe' effective heating vsurface* of the' boiler system, vertieal head,

ers to. r'vhiohf'the' banks of .tubes are connected xatlitheir ends, steam drums oonne'e'ted' to thevert'iealheaders, fuel jets-in theroof ofv vthe Combustion chamber` for proj eating the gases bf Combustion downwardly through spaced belowv the heating j chamber, water' screens' connecting'the1 'steaml .and water residue 'or ash bustion. y Y I l In witness whereof, I have `hereunto signed by naine this 22nd 'day of-July 192,5,l ALFRED WILLIAM BENNIS, i 

